Horii Takuro, Yanagisawa Eikichi, Kimura Mika, Morita Sumiyo, Hatada Izuho
Biosignal Genome Resource Center, Institute for Molecular and Cellular Regulation, Gunma University, Japan.
Cell Reprogram. 2010 Oct;12(5):551-63. doi: 10.1089/cell.2009.0104.
Embryonic stem (ES) cells constitute a very important tool for regenerative medicine today. These ES cells, and human ES cells in particular, are almost all derived from embryos obtained by in vitro fertilization (IVF) and from in vitro culture (IVC); however, such in vitro manipulated embryos often show abnormal genomic imprinting, which can lead to the development of various diseases. Nevertheless, several reports have evaluated ES cells derived from in vitro manipulated embryos. In this study, we established ES cells derived from both in vivo and in vitro developed blastocysts (Vivo ES cells and Vitro ES cells, respectively) to compare the methylation status of imprinted genes and gene expression patterns. At very early passages, Vitro ES cells showed an increase in abnormal genomic imprinting compared to Vivo ES cells. In addition, we found that the gene expression patterns of several methylation related-genes frequently shifted to promote demethylation and to inhibit methylation in early-passage Vitro ES cells. In contrast, at later passages, we found no significant differences between Vivo and Vitro ES cells. In conclusion, it is advisable to use early passage Vivo ES cells whenever feasible, or to select ES cell lines with a normal epigenotype.
胚胎干细胞（ES细胞）如今是再生医学中非常重要的工具。这些ES细胞，尤其是人类ES细胞，几乎都来源于通过体外受精（IVF）获得的胚胎以及体外培养（IVC）；然而，这种体外操作的胚胎常常表现出异常的基因组印记，这可能导致各种疾病的发生。尽管如此，已有数篇报道对来源于体外操作胚胎的ES细胞进行了评估。在本研究中，我们分别从体内和体外发育的囊胚中建立了ES细胞（分别称为体内ES细胞和体外ES细胞），以比较印记基因的甲基化状态和基因表达模式。在极早期传代时，与体内ES细胞相比，体外ES细胞的异常基因组印记有所增加。此外，我们发现几个与甲基化相关基因的基因表达模式在早期传代的体外ES细胞中频繁转变，以促进去甲基化并抑制甲基化。相反，在后期传代时，我们发现体内和体外ES细胞之间没有显著差异。总之，只要可行，建议使用早期传代的体内ES细胞，或者选择具有正常表观基因型的ES细胞系。
